1. Field of the Invention
The present invention relates to a method for determining the concentration of an absorbable component in a gaseous mixture.
2. The Prior Art
A great many widely differing methods for determining the content of individual components in gaseous mixtures are known. These methods are based on physical, physico-chemical or purely chemical properties of the component which is to be determined in relation to the other components in the gaseous mixture.
One group of methods is based on the isolation of the component in question from the gaseous mixture by absorbing it in a suitable absorption liquid, whereby according to circumstances the absorption may be purely physico-chemical in nature or may be accompanied by a chemical reaction. The subsequent measurement of the quantity absorbed may then be performed by chemical methods or by measuring appropriate concentration-related physical or physico-chemical properties of the liquid phase.
In accordance with an existing absorption method, a stream of absorbent material of known size is brought into intimate contact with a stream of known size of a gaseous mixture of which the concentration of a given component is to be determined. The choice of a suitable absorbent material will ensure that the absorption process will be accompanied by a change in the heat content, which will cause the heating up of the mixture of the stream of absorbent material and the stream of gas. Under certain circumstances, this rise in temperature will provide an indication of the concentration of the absorbed component in the gas flow. The method calls for the effective thermal insulation of the absorption section, just as it demands the precise metering of the size of both the stream of absorbent material and the stream of liquid, these streams being brought into thermal equilibrium before absorption takes place. The resulting increase in temperature will more often than not be very small and will require precise measuring equipment. The time constant for the measurements is highly significant in view of the thermal capacity and conductivity of the walls and of the insulating material.